With the spread of avian influenza into U.S. dairy cattle raising concerns that the virus could spark a pandemic, the head of the White House Office of Pandemic Preparedness and Response Policy urged scientists to adopt a “deep sense of humility” when communicating potential risks to the public. 

“We’ve been saying avian flu is likely to cause a pandemic for 30 years, and we’ve been consistently wrong,” said Major General (Ret.) Paul Friedrichs, speaking Friday at a #TropMed24 symposium. “We need to be exceptionally objective in describing what the actual risk is versus our concerns. … As we look at what has caused pandemics (in the past), we are not yet at the point where we are successfully able to predict when or where the next outbreak will occur.”

Friedrichs noted that thus far, human infections linked to the dairy cattle outbreak of the virus, which is technically known as H5N1, have been “thankfully mild.” But the rapid spread of the H5N1 among a number of mammalian species “should cause concern,” he said, and points to the need for much “greater surveillance.” 

He said the fact that surveillance in the United States is heavily dependent on state and local health agencies demonstrates the importance of building partnerships. For example,  experts should look for ways to convince state and local agencies to participate in wastewater surveillance initiatives, but without adopting a “top-down finger wagging” tone, he said.

Friedrichs said he is not trying to minimize the risk of avian influenza moving from animals to humans, and he lauded the tremendous efforts on multiple fronts over the last eight months to stay abreast of the threat. Rather, he simply wants to highlight “that there has never been a pandemic or biological event in which we anticipated every aspect of it.” He said that exercising caution in framing the pandemic threat posed by the H5N1 virus is essential to rebuilding public trust in the science that was diminished during the pandemic. 

Meanwhile, Friedrichs said federal officials already have made available 700,000 diagnostic tests and could quickly order another million if there is a sudden surge in demand. He also noted that there are a million doses of vaccines in the national strategic stockpile and plans are in place to provide a million more if needed. Friedrich also said that the ability to rapidly develop protective monoclonal antibodies (mABs) — something that did not exist five years ago and is improving on an almost daily basis — adds a new dimension to U.S. pandemic response planning. 

Also at the symposium, Nahid Bhadelia, director of the Boston University Center on Emerging Infectious Diseases, discussed her work with a panel convened by the U.S. National Academy of Sciences, Engineering and Medicine that released a report this week outlining potential research priorities to inform readiness and response to an avian influenza outbreak. She said one issue that generated considerable discussion among panel members is that the U.S. is not sufficiently prepared to quickly detect a new respiratory virus circulating in humans. 

“We don’t have a good structure for (monitoring) seasonal influenza or COVID-19 or RSV on an ongoing basis,” she said. “Having a platform that allows us to study respiratory viruses that are seasonal also provides the capacity to (detect) any new viruses that are walking into our clinics or emergency rooms.” 

She also said it’s still not clear why the recent human cases of avian influenza linked to the dairy cattle outbreak have been relatively mild, while, historically, H5N1 has been associated with a high fatality rate. (Bhadelia noted that the Canadian teen hospitalized this week in critical condition was infected by with a genotype of H5N1 that likely came from poultry and is different from the one what’s circulating in U.S. dairy cattle.)  

“The pending clinical questions for me is why are the more recent cases milder,” Bhadelia said. “Is it just sampling bias? Is it just (viral) dose or mode of transmission?” 

She said the CDC did a study in ferrets, the animal long used to assess influenza viral risks in humans, and the mortality rate of ferrets infected with the strain circulating in U.S. dairy cattle was “pretty high.”

Gregory Gray, an infectious disease expert with the Global Health University of Texas Medical Branch (UTMB) in Galveston, who has been tracking the outbreak in dairy cattle, said H5N1 has now spread to more than 500 farms in 15 states. 

“It is not well-controlled yet,” Gray said. “So, there is a lot of concern that the virus is becoming a bigger threat than ever before right here in North America.”

He said that while the virus appears to be confined to dairy cattle, its potential spread to beef cattle worries him. But efforts to intensify surveillance on U.S. cattle farms are encountering significant pushback from the livestock industry in North America, he said, where the prevailing view is that farmers already have the ability to detect the virus. 

“We need to find mutual areas of cooperation and we need to bring (industry) to the table and say it’s to your advantage to work with us because you can save costs from morbidity,” he said. 

Gray noted that he’s hopeful that are pathways to better partnerships. He said a recent one health conference organized by UTMB  attracted a lot of participation from industry.